Last week Dianne Hackborn explained some of the Android graphic pipeline internals...
... and then a huge discussion on Google+ broke loose, very good insights!
JSON in Android - Tutorial(vogella.de)
This tutorial explains the basic use of JSON in an Android project.
New Layout Widgets: Space and GridLayout(android-developers.blogspot.com)
The new gridlayout for widgets explained.
Android Section List(code.google.com)
This library provides you iOS style lists with sections on your Android.
A screencast on how to deal with SQLite databases on Android.
A music app that shares what you're listening with your friends.